These two forms are a dialect (variation?) of English, mostly used in Southern USA.
Also, if I remember my John McWhorter correctly:
1) "y'all" refers to a group majority (e.g. a group of 10 people within the global collective of 20)
2) "all y'all" refers to the complete set (all 20)
Both of these are contextually narrow than "you" which can refer to a single person or to an undefined sized group.
A possibly better example would have actually been "thou", an archaic singular 2nd person pronoun.
However, all of this is just further proof that the equivalence in conjugation is a harder problem that could be imagined. So, thank you for contributing a good example.
These two forms are a dialect (variation?) of English, mostly used in Southern USA.
Also, if I remember my John McWhorter correctly: 1) "y'all" refers to a group majority (e.g. a group of 10 people within the global collective of 20) 2) "all y'all" refers to the complete set (all 20)
Both of these are contextually narrow than "you" which can refer to a single person or to an undefined sized group.
A possibly better example would have actually been "thou", an archaic singular 2nd person pronoun.
However, all of this is just further proof that the equivalence in conjugation is a harder problem that could be imagined. So, thank you for contributing a good example.